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Structural variations on N ‐acetylneuraminic acid, 16. A convenient approach to 3‐deoxy‐ D ‐ glycero ‐ D ‐ galacto ‐nonulosonic acid (KDN), 5‐azido‐5‐deoxy‐KDN and 5‐deoxy‐KDN, and their 4‐methylumbelliferyl 2α‐glycosides
Author(s) -
Schreiner Erwin,
Zbiral Erich
Publication year - 1990
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.1990199001107
Subject(s) - chemistry , hydrazoic acid , toluene , acetic acid , derivative (finance) , sialic acid , glycoside , organic chemistry , catalysis , stereochemistry , medicinal chemistry , biochemistry , financial economics , economics
The reaction of peracetylated N ‐acetylneuraminic acid methyl ester 1 with nitrosyl acetate affords a mixture of anti / syn ‐ N ‐nitroso derivatives 2a and 2a ′, which can be transformed with sodium trifluoroethanolate into the 5‐diazo compound 3 . The reaction of 3 with tetrabutylammonium acetate/acetic acid yields methyl 2,4,5,7,8,9‐hexa‐ O ‐acetyl‐3‐deoxy‐ D ‐ clycero ‐β‐ D ‐ galacto ‐2‐nonulopyranosidonate (KDN) ( 4a ). On the other hand, 5‐azido‐5‐deoxy‐KDN ( 5a ) is formed by treating 3 with hydrazoic acid in toluene. Heating of 2a / 2a ′ in toluene furnishes a mixture of the peracetylated deaminated furanoid sialic acid derivative 10 with probably changed configuration at C‐5 and C‐6 and the deaminated 5,6‐ and 4,5‐didehydrosialic acid derivatives 6 and 7 . Catalytic hydrogenation of 6 and 7 yields the 5‐deoxy‐KDN derivative 9a and ‐ after hydrogen‐olysis of the 4‐acetoxy group ‐ a minor amount of compound 8 . The compounds 4a , 5a , and 9a have been converted into the free deaminated sialic acids 4e , 5e , and 9e via the 4‐me‐thylumbelliferyl 2α‐glycosides 4c , d , 5c , d , and 9c , d .